I had a 17C and I kick myself for getting rid of it. Much soffter shooting. You do have the "rabbit ears" that appear when firing, from the comp slots but they do not impede your ability to maintain sight picture.
A friend shoots a 21c and it is smooth and accurate. I have yet to shoot the 10mm so I'm not sure about recoil but sight picture should not be affected.
The only real negitive is total loss of night vision when 1st round goes downrange. Even though you are affected with a uncompensated pistol the comp slots will spit out a lot of flame, and it will be right in front of your face vs. out the end of a barrel.
I personally feel the positive outweighs the negetive if you want a softer recoil. My opinion.

If you use the gun for defense - versus outdoor/range use - you may have to fire from the retention position. This has the pistol on the side against the strongside pectoral muscle. Firing a vented gun from this position will direct hot gas and particles directly into your face and eyes. This is undesirable to say the least when you are fighting for your life.

Vented/compensated guns are fine for hunting or range shooting, but not great for defense.

i am looking at this gun primarily as a woods/outdoor protection pistol(live in ga, 10mm should take care of anything i run into) but will not use it for hunting. i will obviously shoot at the range to better myself with it, so the vents are no problem there. but you never know how you will have to defend yourself. i like the idea of reduced recoil but i don't want hot gas/air in my face in a critical situation. ill probably get the non-compensator model due to the variety/ unpredictability of situations that may occur.